To provide an ignition device capable of widely securing an inner space for providing a communication ignition circuit.

In the ignition device 11, the communication ignition circuit 14 is provided between a header part 13 with a plurality of pins 12 for bus connection held by a header part main body 26 and an explosive part 15. The plurality of pins 12 are insulated from the conductive header part main body 26 and electrically connected with the communication ignition circuit 14 and the header part main body 26 is contacted with a conductive cap 16 covering the explosive part 15 and the communication ignition circuit 14.